1. Field of the Invention
This invention relates generally to devices for implementing a ground connection and, more particularly, to a ground connector for terminating heavy gauge solid ground wire at a cable shield ground clamp.
2. Description of the Related Art
A number of devices have been employed for connecting the tubular ground shield of service wires to a common ground point. Most conventional devices employ clamp assemblies of various forms. In applications to which the present invention relates, the ground connection devices are positioned within a cabinet or housing which may hereafter be referred to as a network interface device (NID). A NID is typically a weather-resistant, rigid plastic housing that may be mounted to a telephone pole or on the outside of a home. The NID receives service wires and includes connection terminals for linking a network to inside wiring. The buried service wires are typically comprised of multiple, concentric, protective layers surrounding several pairs of signal-carrying wires. The outer layer of a service wire is typically a heavyweight, flexible rubber or plastic, referred to as a jacket or sheath. Inside the jacket is typically arranged a tube-like metallic ground shield. Within the ground shield there may be another layer or layers of plastic or rubber surrounding and protecting the signal wires, otherwise known as pairs.
The NID is typically mounted to a pole or on the outside of a home and the service wire arranged to enter the cabinet through one of several grommet-covered entry openings. The NID is typically mounted so that the entry openings are directed downwardly. After passing through the rubber or elastic grommet, the ground shield of the service wire must be connected to a common ground point within the NID. U.S. Pat. No. 5,597,314 (hereinafter the ""314 patent), assigned to the assignee of the present invention, discloses a cable-shield ground clamp for implementing such a ground connection. The cable shield ground clamp comprises a generally U-shaped yoke whose generally parallel legs define a service-cable-receiving aperture. The legs of the yoke have opposed, threaded surfaces. A keeper is threadable with the legs of the yoke and torquable for displacement relative to the yoke. The keeper includes a clamp jaw that is compressably engageable against the ground shield of a service wire received in the aperture. The yoke includes a screw or other means for connecting an end portion of the yoke to a flexible ground lead for implementing the ground connection with a common ground point.
U.S. Pat. Nos. 5,722,840 and 6,322,378, both assigned to the assignee of the present invention, disclose trough-like, rigid pair protectors which are configured to substantially surround the signal pairs when inserted within the ground shield of a service wire. The service wire and received pair protector are then received in the aperture of the ""314 cable shield ground clamp. This arrangement allows the ground clamp to be torqued such that a reliable and secure ground connection is developed between the clamp and the cable ground shield without damaging the conductor pairs. The pair protector is sufficiently rigid to withstand pressure from the jaw of the ground clamp and protect the signal pairs within. The pair protector may be of particular utility when the signal wires are optical fibers and prone to crushing or other damage. Further, the pair protector disclosed in U.S. Pat. No. 6,322,378 discloses a conductive extension that projects an electrical connection with the shield to a point outside the cable jacket, obviating the need to remove the cable jacket and improving the strength of the assembled service wire and clamp.
The ground clamp is installed to the service cable after the service cable has passed through a grommet leading into the enclosure or NID. Many modern enclosures or NIDs are manufactured from molded plastics or other engineering materials that are substantially nonconductive. It, therefore, is necessary to implement a ground connection to a common network ground point within the enclosure to protect against lightning strikes and provide for noise suppression, etc., as is known in the art. Frequently, the ground connection enters the enclosure in the form of a heavy-gauge, solid copper or aluminum wire along a path parallel to the buried service wire. It may be difficult to establish a reliable connection between such a heavy-gauge, solid wire and the common ground point in the enclosure or NID. This is due to the limited space inside the enclosure or NID and the fact that the hardware inside the NID is often not compatible with the size and rigidity of such a solid ground wire.
There is a need in the art for a compact, efficient and reliable means for connecting a heavy-gauge, solid ground wire to a common ground point within a NID.
Briefly stated, the invention comprises a lug configured for permanent fixture to a flexible, stranded ground lead where the lug is modified to receive and secure one end of a predetermined gauge, solid ground wire. The modified lug is further configured to secure to the upper cap or end portion of the yoke of a cable shield ground connector as described in the ""314 patent. A service wire and solid ground wire may thus be terminated immediately inside a NID and the ground connection for both carried to a common ground point by the flexible ground lead. The flexible ground lead may be pre-installed in the NID.
An object of the present invention is to provide a new and improved means of grounding a network interface device.
Another object of the present invention is to provide a new and improved connector for a solid ground wire entering a NID of space-efficient design.
A further object of the present invention is to provide a new and improved means of establishing a connection between a solid ground wire entering a NID and the NID circuitry that minimizes installation steps.